What is the Zero-Based Budget?
Zero-based budgeting means income minus allocations equals zero — every rupee is assigned a purpose before the month starts, including savings. Nothing is left "floating", which is where unplanned spending normally hides.
It is more demanding than the 50/30/20 rule but far more precise, and it is the method most likely to expose where money genuinely disappears.
Formula & worked example
Worked example: ₹80,000 income with ₹22,000 housing, ₹12,000 food, ₹6,000 transport, ₹5,000 bills, ₹8,000 debt and ₹20,000 savings = ₹73,000 allocated, leaving ₹7,000 unassigned. That ₹7,000 is exactly the amount that vanishes each month without a plan — assign it to savings or a specific category and the budget balances.
How to use this zero-based budget calculator
- Enter your reliable monthly income, excluding bonuses.
- Fill every category using your last three months of actual spending.
- Treat savings as a bill, not as leftovers.
- Adjust until "Unassigned" reaches zero — that is the whole point.
Smart tips
- Unassigned money is not a surplus; it is next month's mystery expense. Name it now.
- Build the budget from your last three months of statements, not from what you think you spend.
- If you are overspent, cut the largest flexible category first — usually food delivery and subscriptions.
- Redo it monthly. A zero-based budget is a plan for one specific month, not a permanent template.
Frequently asked questions
What is zero-based budgeting?
A method where you allocate every rupee of income to a category — spending, saving or debt — until nothing is unassigned. The balance must reach exactly zero.
Is zero-based budgeting better than 50/30/20?
It is more accurate and better for tight budgets or irregular income. 50/30/20 is simpler and easier to sustain long-term.
What if I have money left over?
Assign it deliberately — to savings, debt or a sinking fund. Leftover money with no name is the most common source of budget leaks.
How do I zero-base an irregular income?
Budget on your lowest recent month. Allocate surplus from better months to a buffer fund that smooths the weak ones.
Want the theory behind the numbers? Read our budgeting guides on the Money Blog.